Download of MConvert 9.0 for Mac was available from the developer's website when we last checked. We cannot confirm if there is a free download of this app available. The actual developer of this software for Mac is White Wizard Productions.
You can set up MConvert on Mac OS X 10.6.6 or later. The application's installer is commonly called mconvert.pkg. We recommend checking the downloaded files with any free antivirus. The most popular versions of the software are 9.0 and 8.2. The software lies within System Tools, more precisely Virtualization. This application's bundle is identified as com.nickolbe.mconvert.
From the developer:
MConvert is the best solution for conversion of measurements, including the following 27 conversion groups and many subgroups:
Acceleration, Angle, Area, Base, Consumption, Currency, Data Storage, Data Transfer, Density, Energy, Energy/Mass, Force, GPS, Illuminance, Length, Luminance, Mass, Permeability, Power, Pressure, Radioactivity, Temperature, Time, Torque, Velocity, Viscosity, Volume.
You may want to check out more Mac applications, such as Bigasoft WebM Converter, which might be related to MConvert.